Uniting Community Ecology and Evolutionary Rescue Theory: Community-Wide Rescue Leads to a Rapid Loss of Rare Species

Abstract

Most ecological communities are facing changing environments, particularly due to global change. When migration is impossible, adaptation to these altered environments is necessary to survive. Yet, we have little theoretical understanding how ecological communities respond both ecologically and evolutionarily to such environmental change. Here we introduce a simple eco-evolutionary model, the Community-Wide Rescue (CWR) model, in which a community faces environmental deterioration and each species within the community is forced to undergo adaptation or become extinct. We assume that all species in the community are equivalent except for their initial abundance. This individual based simulation model thus combines community ecology and evolutionary rescue theory. We show that under Community-Wide Rescue a rapid loss of rare species occurs. This loss occurs due to competition and a limited supply of beneficial mutations. The rapid loss of rare species provides a testable prediction regarding the impact of Community-Wide Rescue on species abundance distributions in ecological communities.

The importance of species interactions in eco-evolutionary community dynamics under climate change

“…In addition, temperature-dependent competition significantly reduces global species loss. With constant competition as in our baseline scenario, competitive exclusions occur to a higher extent, a result in line with van Eldijk et al 10 , showing that evolutionary rescue of one species leads to a competitive exclusion and extinction of another species. The importance of biotic interactions for shaping species' response to climate change is wellknown 8,10,15,16 .…”

“…With constant competition as in our baseline scenario, competitive exclusions occur to a higher extent, a result in line with van Eldijk et al 10 , showing that evolutionary rescue of one species leads to a competitive exclusion and extinction of another species. The importance of biotic interactions for shaping species' response to climate change is wellknown 8,10,15,16 . Our work complements these studies by further demonstrating the significance of biotic interactions in an ecoevolutionary setting as well.…”

“…Moreover, species interactions can both alleviate and aggravate the impact of climate change on species 8 , and interact with other eco-evolutionary processes. For example, species interactions can affect a species' evolutionary response to altered environmental conditions 9,10 ; and dispersal may release a species from negative interactions through migration 11 or increase them through invasion 12 .…”

Threatened fish species in the Northeast Atlantic are functionally rare

“…Therefore, other species traits such as size and body shape or behaviour must be considered to further explain differences in abundance (Walker et al, 2017). What is certain is that less abundant species are less resilient to abrupt environmental changes (Bell & Gonzalez, 2011), and anthropogenic pressure such as habitat degradation and overfishing-that we can be related to the anthropogenic Allee effect; for example, Courchamp et al (2006)due to a limited supply of beneficial mutations and interspecific competition with more common species that have already undergone such beneficial mutation (Bell, 2017;van Eldijk et al, 2020) and competitive exclusion as they are less able to exploit their habitat (Segre et al, 2014). Here, we reveal that the abundance of the most functionally distinct species is low across the Northeast Atlantic, with maximum richness and abundance being found on the Porcupine Bank (see Supporting Information Appendix S2-Figure S5), although this region is one of the less well sampled of the European Porcupine Bank and adjacent areas support an important European demersal fishery, which makes these deep-sea species highly vulnerable to bottom trawl bycatch (Oliver et al, 2015), especially those for which abundance data do not support the implementation of management measures (ICES, 2021).…”

Genotype specific and microbiome effects of hypoxia in the model organism Daphnia magna

“…The decrease over time might indicate adaptation of the microbiome after the microbiome transplant to favour the host performance. Although random processes could also lead to a drop in rare species after an environmental deterioration, a sudden drop of many species could potentially indicate an evolutionary rescue (van Eldijk et al, 2020). When donors were pre-exposed to normoxia, the decrease in time was only found within the KNO recipient genotype.…”